Carleton



(No Model.)

.0. W. NASON'.

SAFETY APPARATUS FOR AUTOMATIC DRAFT REGULATORS.-

Paterited Mar. 2, 1886.

EJNKTED STATES PATENT @Tricn.

OARLETON W. NASON, OF NEXV YORK, N. Y.

SAFETY APPARATUS FOR AUTOMATIC DRAFT-REGULATORS.

iPEGIl-IQATION forming part of Letters Patent No. 337,013, dated March2, 1886.

Application filed January 16, 1886. Serial No. 188,738.

To all whom it may concern:

Be it known that I, CARLETON W. N ASON, a citizen of the United States,residing at New York, county of New York, and State of New York, haveinvented certain new and useful Improvements in Safety Apparatus forAutomatic Draft-Regulators, fully described and represented in thefollowing specification and the accompanying drawings, forming a part ofthe same.

This invention relates to that class of draftregulators in which thedoor or doors or dam per or dampers of the furnace is or areautomatically closed and opened to diminish and increase the draft bymeans of a diaphragm, which is subj ected to the pressure inthesteamboiler, and is arranged to rise and fall as the pressure in theboiler increases and diminishes, and thus through suitable connectionsoperate the furnace door or doors or damper or dampers, as stated. Theregulators of this class, although applicable to all furnaces which areused in connection with a steamboiler, are more particularly useful inconnection with furnaces and boilers which are used for heatingpurposes, and which are usually operated without the attendant beingpresent, except at intervals.

The connections between the diaphragm and the furnace door or doors ordamper or dampers usually consist of a rod or follower, which rests uponthe upper side of the diaphragm, and is connected to a pivoted lever,which is in turn connected by a rod or chain to the door or doors ordamper or dampers which is or are to be operated. This lever is providedwith a counterbalancing weight or weights, so adjusted upon the lever asto hold the rod or follower against the diaphragm, but at the same timeso nearly balance the lever that comparatively little power will berequired torock it. These-parts are so adjusted that when the diaphragmis in its normal positionthat is to say, when the ordinaryworking-pressure exists in the boiler, the furnace door or doors ordamper or dampers will be held sufficiently open to allow the properamount of draft.

The diaphragm upon which the rod or follower rests is usually made ofrubber, and it has been found in practice that the rubber, after havingbeen for a long time in use, is liable to become so weakened that if itis subjected to a (No model.)

considerable pressure it willsometimes break. There is also, of course,more or less liability of the diaphragm being defective, so that it willbreak even before it has been long in use.

From what has been said it will readily. be seen that whenever from anycause the diaphragm breaks, the rod or follower and the lever willremain in or at once fall to their normal position, thereby keeping openthe draft, regardless of the steam-pressure in the boiler. If thereshould happen to be a considerable body offucl in the furnace, and theattendant should not happen to be present, there being nothing to checkthe draft,the fuel would continue to burn, and the steam-pressurein theboiler might, and probably would, be increased to such a degree as tooccasion serious danger,and perhaps damage.

It is the object ofthe present invention to avoid this difficulty anddanger, and to provide means by which, in case the diaphragm breaks, thefurnace door or doors or damper or dampers, instead of remaining open,or being at once opened, so as to continue or increase the draft, willbe at once closed, so as to 'shut off all draft, and thus prevent theburning of the fuel and the increase of the steam-pressure in theboiler:

As a full understanding of theinvention can be best imparted by adetailed description of the apparatus in which it is embodied, suchdescription will now be given, reference being had to the accompanyingdrawings,in which- Figure 1 is a side elevation of the apparatusembodying the invention in one form, the parts being shown in theirnormal position. Fig. 2 is sectional elevation of the same, the partsbeing in the same position. Fig. 3 is a view similar to Fig. 2, showinganother embodiment of the invention; and Fig. 4 shows a detail, whichwill be hereinafter referred to.

Referring to said figures, it is to be understood that A represents thebody or chamber of the apparatus; a, the flexible diaphragm containedtherein; B, the pipecommunicat ing with the steam-boiler, and with thechamber A beneath the diaphragm; the rod or follower, which extendsthrough the top of the chamberA, and is provided with a head, a, whichrests upon the upper side of the diaphragm; D, the lever to which therod G is.

' connected, and which is fulcrumed to a'stud,

d. rising from the side of the chamber A; E, the chain connecting thelever D with the fur nace door or doors or damper or dampers, and F thecounterbalancing-weight, which is so adjusted as to rock the lever D andhold the head 0 of the rod 0 pressed against the diaphragm a. The partof the chamber A above the diaphragm communicates freely with the openair through the opening around the rod 0; but the part of the chamberbeneath the diaphragm is closed from the outside air. The pipe B isprovided with the usual goose-neck, b, which, together with the portionof the pipe above the goose-neck and the space in the chamber A beneaththe diaphragm, is filled with water, which serves to keep the diaphragmmoist, and also prevents the steam from coming into contact with thediaphragm, and thus injuring it by reason of the heat.

The organization thus briefly described is of substantially the commonform, and will be readily understood by those familiar with this classof apparatus.

The several parts of the apparatus, as before stated, are so adjustedthat as long as the pressure of the steam in the boiler does not riseabove what is required for the work to be performed the parts willremain in the position shown in Figs. 1 and 2-that is to say, the end ofthe lever to which the chain E is connected will be rocked upward, so asto hold the furnace door or doors or damper or dampers open sufficientlyto permit theproper draft to maintain the steam-pressure in the boiler.If, however, at any time the pressure in the boiler increases beyondwhat is safe, this increased pressure will be communicated to thediaphragm a, so as to raise the latter and, through the rod 0, rock thelever D, and permit the furnace door or doors or damper or dampers toclose, and thus diminish the draft and reduce the pressure in theboiler. As the pressure in the boiler is thus reduced, the diaphragm awill fall back to its normal position, thus permitting the end of thelever D, to which the chain E is connected, to again rock upward andopen the draft. It is to be re marked in passing that in some cases theend of the lever D opposite to that to which the chain E is connected,is connected by a chain or rod with a door or damper located above thefire, so that as the draft is closed by the raising of the diaphragm,and the consequent downward movement of one end of the lever, the dooror damper above the fire is opened to admit air at that point, and thusfurther deaden the fire, and vice versa.

From the foregoing it will be seen that whenever, from any cause, thediaphragm a becomes broken the pressure in the boiler will no longer becommunicated to the rod 0, and, as a consequence, the lever D willremain in its normal position, so as to keep the furnace-draft open,regardless of the pressure in the boiler, and this, as before explained,is

liable to occasion danger and damage. In order to avoid this, I providethe chamber A with a laterally -projecting pipe, G, which communicateswith the chamber at a point above the diaphragm a, and extends to apoint near the chain E, where it terminates in a small chamber, (seeFigs. 1, 2, and 4,) having openings at its top and bottom, through whichthe chain E passes. The chain E,where it passes through the chamber 9,is provided with a link, 6, which is made of soft solder or othersubstance which melts at a comparatively low temperature.

From this construction it results that as soon as the diaphragm abecomes broken the body of water confined beneath the diaphragm and inthe\ upper end of the pipe B will be forced out through the pipe G andthe opening around the rod 0, after which the steam will also pass outthrough the pipe G and into the casing g,where its heat will besufiicient to danger of the boiler bursting or becoming damaged.

It will be seen from what has been said that the gist of theconstruction just described con sists in the location of the fusiblelink e in such position that it will be exposed to the heat of the steamwhich is released by the breaking of the diaphragm a. It will also beseen that for this purpose the link may be located in other positionsthan that shown in Figs. 1 and 2. For example, it may be located whollyor partly inside the chamber A, above the diaphragm, as shown in Fig. 3.In this the pipe G and chamber gare dispensed with, and the chain E iscarried to the outer end of the lever D over one or more small pulleysh, mounted in bearings upon the lever. In this case, as soon as thediaphragm a becomes broken,t-he water confined beneath the diaphragmwill be forced out through the openings around the rod 0 and the link e,and the steam will enter the chamber, so that its heat will melt thelink 0 and break the chain E; or the link 6 may be located in any otherdesired position, so long as its, position is such that it will beexposed to the steam which is released by the breaking of the diaphragm.

In the organization shown in Figs. 1 and 2 it may sometimes be founddesirable, in order to render the operation more certain, to provide thechain E, beneath the chamber g,with a receptacle or cup, as H, whichwill receive the water expelled through the pipe G. By this means theweight of this water is thrown upon the link 6, thereby putting anadditional strain upon the link, which will tend to insure its beingbroken. In some cases the weight of this water may be sufficient to rockthe lever D and close the draft, even if the steam should fail to meltthe link e.

What I claim is 1. In a draft-regulator, the fusible link 6,

located in position to be exposed to the steam released by the breakingof the diaphragm of the regulator, substantially as described.

2. The combination, with the diaphragm a 5 and lever D, operated by thediaphragm, of the chain or rod E, having the link 6 located in positionto be exposed to the steam released by the breaking of the diaphragm,substanf tially as described.

10 3. The combination, with the chamber A, diaphragm a, and lever D,operated by the diaphragm, of the chain or rod E, having the cup H, andthe pipe G, communicating with the chamber and arranged to conduct thewater from the chamber to the cup upon the 15 breaking of the diaphragm,substantially as described.

In testimony whereof I have hereunto set my hand in the presence of twosubscribing witnesses.

' GARLETON W.- NASON.

Witnesses: HENRY M. LARSON,

THoMsoN H. PALMER.

